1. Technical Field
The present invention is related to an AC loss measuring device for a high-temperature superconductor.
2. Description of the Related Art
Superconductors generally have no resistance to direct current (DC), and thus no loss. When alternating current (AC) flows in the superconductor, however, loss occurs in the superconductor if the current changes with time or the magnetic field changes with time.
Measurement of the AC loss is a very important factor in determining the cooling capacity and the heat inside connections. Moreover, since the AC loss is mainly caused by the change in current and external magnetic field, an alternating current is first applied and then the loss thereof is calculated in an AC loss measuring device for a superconductor.
In the conventional AC loss measuring device for a high-temperature superconductor, an electric current having a certain frequency and amplitude is applied to a superconductor, and then the waveform of the received voltage or electric current is measured. In this conventional method, however, the superconductor may be damaged if an electric current of about 35 A is applied to the superconductor for tens of seconds.
Also, in the conventional AC loss measuring device for a high-temperature superconductor, the preparation for normal operations takes tens of seconds.